me ( ) and some friends just started playing Shadowpriest Shaman Warrior (~2000 mmr). This far it works out pretty well for us. The games against wizcleaves are pretty open and we didn't face anything with two casters that seemed impossible to beat. But we're having trouble with beating:

+ Healer + Healer

As soon as both of them are able to connect to me my health just drops to 30% in like 3seconds. We're turteling the whole game while disarming, fearing, stunning both of the DD's but we always end up beeing stomped into the ground.

Do you have any tips for us, maybe also a general strat for playing ? (right now we're playing defensive, waiting for proccs and switch hard on Resto

Dks can be a real pain for this comp indeed. To be honest, sometimes its actually good to go balls out hard on dk with all cds the second they are about to connect. Dks die absurdly fast and one cc on healer in this time is almost guaranteed a trinket. If the dk looks like he is surviving, make sure your warrior uses the rest of his cds on the enemy healer, same with spriest if dk uses ams/ibf. Against PHDk that strat is pretty much your easiest way out to win. Make sure your healer isnt kiting your warrior with a meleecleave on him like tsg, as you will almost 100% lose if it turns into a chase game. Make sure you use tendrils+shaman rolls with earthgrab for those comps too, it will improve your teams longevity by a ton. Hope I could help.